PVC Frame

Chief Delphi Members:

Can we use PVC glue to hold our PVC frame together? Some of our members remember there being a rule about not using adhesives, and we need to know if there is a special way we need to connect our components.


Goose Creek Robotics

The current rules do not prohibit using PVC glue or any other adhesive, as long as it doesn’t get onto the field or provide traction.

I’d try to stay away from pvc if at all possible If I was you
Edit: framing use

Do you have some reason for that statement? PVC can be quite strong, and in the right application, it can be one of the best things for the job. (330’s arm in 2005 comes to mind, as does 71’s wings in 2002.)

By frame, I assume you mean chassis, and if that is the case, the thick stuff might be strong to a human applying a load, but can snap if the load rate is high enough (i.e. getting rammed by another robot). Thinner stuff is more deformable, mainly purely because of the thickness, but I am pretty sure the rules call for a rigid frame since the dimensions cannot change.

That is true when used in the proper way. I just don’t think that it could withstand the stresses of being used as a frame. I suposed if you truss it correctly then all will be fine but won’t it bend, flex, or maybe even break when crashing into another bot?

I wouldn’t say a PVC frame is a particularly good idea, but PVC on robots is not always to be avoided. At least 3 of 71’s Championship winning robots had PVC appendages. 330’s 2005 robot and 217’s 2008 robot used PVC. If it’s good enough for World Champions, it’s good enough for me! (sometimes, in the right applications)

Personally I would run any kind of PVC frame through the ringer to ensure it can hold up in competition. I highly doubt it would.

That is true. Depending on where it is used as a frame, of course-- if it’s simply a cage to keep soccer balls out, it’s probably going to be fine for most matches. If it’s the drive chassis, you probably want to rethink the design.

Even some of the big stuff can flex. I think the best way to demonstrate this is to hang a robot off a piece of 2" (or was it 3"?) PVC that’s about 4-5 feet long and supported only at the ends. It’ll flex. I’ve seen it. But it didn’t break.

Let me add to my previous post…

You say “the right application” which I completely agree with. 1279 has used pvc every year since our inception. I think PVC cement is allowed since there aren’t many restrictions on adhesives anymore. (I wonder if cement was restricted before adhesives were allowed… thinks back… o well) PVC robot chassis would be the first I have seen. But hey, prove us wrong… and send me some sweet pics if you do it.

Ok then we are on the same page. Lol sory about that had to make sure.

If you are going to use PVC, I would suggest you talk to 1058, the PVC Pirates. This team uses PVC in some unique way on their robot every year. I am always amazed at their creative use of the material, and the durability of their robot.

One thing to consider is using ABS instead of PVC. ABS is less brittle than PVC which means it will tend to bend in situations where PVC would break. For more info about the pros and cons of both ABS and PVC check out this link

http://www.spudtech.com/content.asp?id=14

Its not exactly the same application (spud guns vs robots) but the info is still good

Hope this helps’
Danny B